This invention relates to a process for the prevention of equipment fouling, e.g., plugging of heat exchangers, with metallic sulfides during the processing and purification of cracked gases.
It is well known that a severe problem is caused by the fouling of equipment with metallic sulfides during the course of the processing of cracked gases produced by the gasification of solid or liquid fuels with steam and oxygen under pressure and elevated temperature, which gases are further processed into H.sub.2 --CO synthesis gases or H.sub.2 --N.sub.2 synthesis gases. It has been recognized that this problem is, in the final analysis, due to metal carbonyls formed during the course of processing of the cracked gases. The metal carbonyls in turn form sulfides with sulfur compounds present in the cracked gas or other compounds used in the process, and these sulfides, in turn, are deposited on certain parts of the apparatus and foul same during the course of time.
To improve these conditions, it has been known from DAS (German Published Examined Application) No. 2,706,152, to cool the raw gas to temperatures of 20.degree.-150.degree. C. and treat the gas with solvents for the extraction, inter alia, of carbonyl-forming metals from the gas. However, it has been found that this conventional process nevertheless results in equipment fouling after a period of time insofar as less than 100% of the carbonyl-forming metals are extracted.